multilib: Only build one kernel

For a given system we only want one kernel to be built. This change makes
the main kernel recipe provide all of the provides of the various enabled
multilibs hence allowing it to fulfil all the appropriate dependencies.

To make this work a global multilib class file needed to be created.

This patch also enables this multi provider functionality for "allarch"
packages.

[YOCTO #1361]

(From OE-Core rev: 2fd257f6c610624f05c8dd3fe1486364af04696f)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/classes/multilib.bbclass

@@ -6,12 +6,17 @@ python multilib_virtclass_handler () {
     variant = e.data.getVar("BBEXTENDVARIANT", True)
     if cls != "multilib" or not variant:
         return
+
+    # There should only be one kernel in multilib configs
+    if bb.data.inherits_class('kernel', e.data) or bb.data.inherits_class('module-base', e.data) or bb.data.inherits_class('allarch', e.data):
+        raise bb.parse.SkipPackage("We shouldn't have multilib variants for the kernel")
+
     save_var_name=e.data.getVar("MULTILIB_SAVE_VARNAME", True) or ""
     for name in save_var_name.split():
         val=e.data.getVar(name, True)
         if val:
             e.data.setVar(name + "_MULTILIB_ORIGINAL", val)
-
+ 
     override = ":virtclass-multilib-" + variant
 
     e.data.setVar("MLPREFIX", variant + "-")
@@ -28,16 +33,6 @@ STAGINGCC_prepend = "${BBEXTENDVARIANT}-"
 python __anonymous () {
     variant = d.getVar("BBEXTENDVARIANT", True)
 
-    def extend_name(name):
-        if name.startswith("virtual/"):
-            subs = name.split("/", 1)[1]
-            if not subs.startswith(variant):
-                return "virtual/" + variant + "-" + subs
-            return name
-        if not name.startswith(variant):
-            return variant + "-" + name
-        return name
-
     def map_dependencies(varname, d, suffix = ""):
         if suffix:
             varname = varname + "_" + suffix
@@ -50,25 +45,15 @@ python __anonymous () {
             if dep.endswith(("-native", "-native-runtime")):
                 newdeps.append(dep)
             else:
-                newdeps.append(extend_name(dep))
+                newdeps.append(multilib_extend_name(variant, dep))
         d.setVar(varname, " ".join(newdeps))
 
-    def map_variable(varname, d):
-        var = d.getVar(varname, True)
-        if not var:
-            return
-        var = var.split()
-        newvar = []
-        for v in var:
-            newvar.append(extend_name(v))
-        d.setVar(varname, " ".join(newvar))
-
     pkgs_mapping = []
     for pkg in (d.getVar("PACKAGES", True) or "").split():
         if pkg.startswith(variant):
             pkgs_mapping.append([pkg.split(variant + "-")[1], pkg])
             continue
-        pkgs_mapping.append([pkg, extend_name(pkg)])
+        pkgs_mapping.append([pkg, multilib_extend_name(variant, pkg)])
 
     d.setVar("PACKAGES", " ".join([row[1] for row in pkgs_mapping]))
 
@@ -87,8 +72,8 @@ python __anonymous () {
         map_dependencies("RCONFLICTS", d, pkg)
         map_dependencies("PKG", d, pkg)
 
-    map_variable("PROVIDES", d)
-    map_variable("PACKAGES_DYNAMIC", d)
-    map_variable("PACKAGE_INSTALL", d)
-    map_variable("INITSCRIPT_PACKAGES", d)
+    multilib_map_variable("PROVIDES", variant, d)
+    multilib_map_variable("PACKAGES_DYNAMIC", variant, d)
+    multilib_map_variable("PACKAGE_INSTALL", variant, d)
+    multilib_map_variable("INITSCRIPT_PACKAGES", variant, d)
 }

meta/classes/multilib_global.bbclass

@@ -0,0 +1,39 @@
+python multilib_virtclass_handler_global () {
+    if not e.data:
+        return
+
+    variant = e.data.getVar("BBEXTENDVARIANT", True)
+
+    if isinstance(e, bb.event.RecipeParsed) and not variant:
+        if bb.data.inherits_class('kernel', e.data) or bb.data.inherits_class('module-base', e.data) or bb.data.inherits_class('allarch', e.data):
+            origprovs = provs = e.data.getVar("PROVIDES", True)
+            variants = (e.data.getVar("MULTILIB_VARIANTS", True) or "").split()
+            for variant in variants:
+                provs = provs + " " + multilib_map_variable("PROVIDES", variant, e.data)
+                e.data.setVar("PROVIDES", origprovs)
+            e.data.setVar("PROVIDES", provs)
+}
+
+addhandler multilib_virtclass_handler_global
+
+def multilib_extend_name(variant, name):
+    if name.startswith("virtual/"):
+        subs = name.split("/", 1)[1]
+        if not subs.startswith(variant):
+            return "virtual/" + variant + "-" + subs
+        return name
+    if not name.startswith(variant):
+        return variant + "-" + name
+    return name
+
+def multilib_map_variable(varname, variant, d):
+    var = d.getVar(varname, True)
+    if not var:
+        return
+    var = var.split()
+    newvar = []
+    for v in var:
+        newvar.append(multilib_extend_name(variant, v))
+    newdata =  " ".join(newvar)
+    d.setVar(varname, newdata)
+    return newdata

meta/conf/multilib.conf

@@ -9,6 +9,8 @@ MULTILIBS ??= "multilib:lib32"
 STAGING_DIR_HOST = "${STAGING_DIR}/${MLPREFIX}${MACHINE}"
 STAGING_DIR_TARGET = "${STAGING_DIR}/${MLPREFIX}${MACHINE}"
 
+INHERIT += "multilib_global"
+
 BBCLASSEXTEND_append_pn-acl = " ${MULTILIBS}"
 BBCLASSEXTEND_append_pn-alsa-lib = " ${MULTILIBS}"
 BBCLASSEXTEND_append_pn-alsa-utils = " ${MULTILIBS}"